Whats the difference if the air filter is closed in or open?

 

Depends on the design, moslty enclosed air systems are made to lessen the debris etc on the air filter meaning less maintenance, they can also assist in sheilding the intake from heat and/or drawing air from a specific area for a colder charge. I chose an open air system to maximize the working space under the hood.

 

Heat causes ****y gas mileage, poor drivability, excessive ware, excessive dirt particals, and water vapor to freeze. Bottom line it is not advised! The better thing to do is pipe in cold air directly from the outside.

 

so air from directly outside. will that help fuel effiency as well as performance?

 

OH YA!

Do a Searchon Ram Air in the 1st generation Durango section.